firefox-user.js

// Don't check for browser defaults
user_pref("browser.shell.checkDefaultBrowser", false);

// Show compact mode UI option, and enable it.
user_pref("browser.compactmode.show", true);
user_pref("browser.uidensity", 1);

// Enable auto-scrolling
user_pref("general.autoScroll", true);

// Enable smooth-scrolling
user_pref("general.smoothScroll", true);

// Prevent alt-scrolling for back/forward navigation
user_pref("mousewheel.with_alt.action", 0);

// Enable scrolling in tab bar to switch between tabs
user_pref("toolkit.tabbox.switchByScrolling", true);

// Don't close on last tab
user_pref("browser.tabs.closeWindowWithLastTab", false);

// Disable Pocket integration
user_pref("extensions.pocket.enabled", false);

// Disable NTP sponsors and recommendations
user_pref("browser.newtabpage.activity-stream.feeds.section.topstories", false);
user_pref("browser.newtabpage.activity-stream.showSponsoredTopSites", false);
user_pref("browser.newtabpage.activity-stream.asrouter.userprefs.cfr.addons", false);
user_pref("browser.newtabpage.activity-stream.asrouter.userprefs.cfr.features", false);

// Disable trending searches
user_pref("browser.urlbar.suggest.trending", false);

// Set default Latin fonts
user_pref("font.default.x-western", "sans-serif");
user_pref("font.name.sans-serif.x-western", "Roboto");
user_pref("font.name.monospace.x-western", "JetBrains Mono NL");

// Enable strict tracking protection
user_pref("browser.contentblocking.category", "strict");

// Enable HTTPS-only mode
user_pref("dom.security.https_only_mode", true);

// Enable DNS-over-HTTPS
// user_pref("network.trr.mode", 3);

// Disable password save
user_pref("signon.rememberSignons", false);